     #include <stdio.h>
     #include <gsl/gsl_rng.h>
     #include <gsl/gsl_randist.h>
     
     int main (void)
     {
       const gsl_rng_type * T;
       gsl_rng * r;
                            
       int i, n = 1000;
       double mu = 50.0;
                                          
       /* create a generator chosen by the 
       environment variable GSL_RNG_TYPE */
                                          
       gsl_rng_env_setup();
                                                 
       T = gsl_rng_default;
       r = gsl_rng_alloc (T);
                                                               
       /* print n random variates chosen from 
       the poisson distribution with mean 
       parameter mu */
                                                               
       for (i = 0; i < n; i++) 
       {
         unsigned int k = gsl_ran_poisson (r, mu);
         printf ("%d,%u,\n", i, k);
       }
                                                                      
       printf ("\n");
       gsl_rng_free (r);
       return 0;
      }
